Field of the Invention
The present invention relates generally to computer aided design (CAD) applications and, in particular, to a mesh skinning technique.
Description of the Related Art
Three-dimensional animation generally involves creating a three-dimensional model or skin, creating a transformation hierarchy for that model, and binding the transformation hierarchy to the model. An animation is a sequence of translations for one or more influences in the transformation hierarchy. When the animation proceeds, the translations that are made to the influences in the transformation hierarchy cause the skin to deform.
Generally speaking, the degree to which any particular part of a skin deforms is related to a value known as a binding weight. Any particular portion of the skin may be affected by a particular influence to a greater or lesser degree based on the binding weight associated with that portion of skin and that particular influence.
Typically, binding weights are assigned manually. There are several drawbacks, however, with assigning binding weights manually. One drawback is that assigning weights is unintuitive, as the impact of assigning a particular weight for a particular pose of the model is not immediately clear to an animator. Another drawback is that assigning weights for a model is time consuming, as each vertex of a model must be assigned a weight.
As the foregoing illustrates, what is needed in the art are improved techniques for assigning skinning weights to a three-dimensional model.